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    SubjectRe: allow non root users to set io priority "idle" ?
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    On Mon, Aug 06, 2007 at 01:11:01PM +0200, Andi Kleen wrote:

    > Very low priority can starve others when it holds some kernel resource
    > needed by another task.

    Nevertheless ordinary users are permitted to lower priority ([re]nice)
    and resource limits (setrlimit).

    > For IO I suppose the same could happen too. e.g. low priority
    > task wants to write out a page and keeps it locked until the IO
    > is finished. High priority task wants to access the page and has
    > to wait until it is unlocked. Middle task generates an endless
    > stream of IO that makes the idle priority writeout never finish.

    I don't quite understand. There are a lot of other ways to starve such
    high-priority process:
    1. renice the low-priority process
    2. send it a signal
    3. ptrace it
    4. use something like cpulimit (http://cpulimit.sourceforge.net/) to stall it
    ....

    So I think current behaviour of ionice is inconsistent (and pointless).

    P.S.
    Please CC me, I'm not subscribed.

    Best regards,
    Alexei

    --
    All science is either physics or stamp collecting.

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